Practical Considerations on the Use of Extreme Sib-pairs for Obesity

Objectives: The extreme sib-pair approach has been shown to be a powerful strategy to identify susceptibility loci linked to quantitative traits. The body mass index is the usually assessed trait in genetic studies on human obesity. Environmental factors clearly play an important role for this trait. We hypothesized that the low weight of most sibs who were seemingly discordant to the obese index proband was influenced by other environmental and/or genetic factors like restrained eating or psychiatric disorders.

Methods: A screening questionnaire was sent to parents of all consecutively admitted patients three weeks prior to referral of index probands for inpatient treatment of obesity. The first 320 families were further investigated. Twenty-seven seemingly extremely discordant sib-pairs (ED) were identified and examined in detail.

Results: The low weight of most sibs who were seemingly discordant to the obese index proband was influenced by factors like restrained eating or psychiatric disorders. Only 20% of the interviewed ED could be considered as genuine ED.

Conclusion: We conclude that extensive medical evaluation is necessary if the aim is to guarantee genuine ED in family studies for human obesity. Non-paternity deserves specific attention in ED studies.

Role of cervical cerclage and prolonged antibiotic therapy with azithromycin in patients with previous perinatal loss amnionitis

In the group of 35 patients with cerclage, intermediate fetal mortality was reduced from 37.1% to 0 (p < 0.001); late fetal mortality rate from 8.5% to 2.8% (p = 0.606); prematurity from 65.7% to 5.7% (p < 0.001); newborn underweight from 11.4% to 5.7% (p = 0.671); newborns with very low weight from 34.2% to 0 (p < 0.001) and the abortion rate from 8.5% to 0 ( p  < 0.001). In the group of 19 patients without buckling, intermediate fetal mortality was reduced from 26.3% to 10.5% (p = 402); late fetal mortality from 63.1% to 0 (p < 0.001); prematurity 78.9% to 31.5% (p < 0.009); the newborn of low weight from 31.5% to 10.5% (p = 0.234); newborns with very low weight from 68.4% to 15.7% (p < 0.003) and the abortion rate from 36.8 to 0 (p < 0.001). In conclusion, we believe the results of this study demonstrate the effectiveness of therapeutic and prophylactic cervical cerclage associated with prolonged antibiotic therapy.

Optimization of in vitro cultivation strategies for human adipocyte derived stem cells

With adipose-derived stem cells being in the focus of research in regenerative medicine, the need arises for fast reliable cultivation protocols. We have tested the cultivation of human adipose-derived stem cells in endothelial cell growth medium prior to induction and differentiation, against the long-established use of DMEM/F12 medium-based cultivation protocols. We found that cultivation in endothelial cell growth medium not only accelerates growth before induction and differentiation, but also allows shorter induction and differentiation times than those following precultivation with DMEM/F12 medium with regard to the formation of mature adipocytes and to the viability undifferentiated cells. These results were first observed morphologically but could be confirmed by performing adiponectin ELISA and cell proliferation assays.

Wechselwirkung kondensierter Molekularstrahlen mit festen Oberflächen

The reflection of a beam of nitrogen clusters from a polished stainless steel surface is investigated. The scattered flux shows a strong maximum at an angle of reflection almost 90°, independent of angle of incidence. The mean velocity of the reflected beam is about equal to the tangential velocity component of the incident beam. Measurements with increased background pressure demonstrate that the reflected beam still consists essentially of clusters.

Constant and variable amplitude ultrasonic fatigue of 2024-T351 aluminium alloy at different load ratios

Ultrasonic fatigue testing equipment is presented that is capable of performing constant amplitude (CA) and variable amplitude (VA) experiments at different constant load ratios. This equipment is used to study cyclic properties of aluminium alloy 2024-T351 in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regime at load ratios R=-1 and R=0.5. CA loading does not reveal a fatigue limit below 10¹⁰ cycles. Cracks leading to VHCF failure start at broken constituent particles. Specimens that survived more than 10¹⁰ cycles at R=-1 contain non-propagating cracks of lengths below grain size. Resonance frequency and nonlinearity parameter β(rel) show changes of vibration properties of specimens at low fractions of their VHCF lifetime. VA lifetimes are measured in the HCF and VHCF regime and compared with Miner calculations. Damage sums decrease with decreasing load (and increasing mean lifetimes) and are lower for R=0.5 than R=-1.

Early warning against airborne radioactivity in Bavaria: Measuring network for radioactive immissions

During the Chernobyl accident it became evident that there was no up to date information of the radiological situation in Bavaria as a whole. Therefore an online measuring network was implemented, which provides radioactivity data around the clock from all over Bavaria. It comprises measuring devices for gamma-dose rate, airborne aerosol and iodine activity and precipitation. The data are processed in accessory computers and transferred to the main network computers in Augsburg by means of a subcenter computer at the site of the IfR-station. Alarm levels are low in order to have an early warning against airborne radioactivity. New techniques for remote maintenance of the measuring devices and nuclide identification are being planned and tested.

Maraviroc can improve lipid profiles in dyslipidemic patients with HIV: results from the MERIT trial

PURPOSE

We investigated the effects of maraviroc, the first approved CC-chemokine receptor 5 (CCR5) antagonist, on blood lipids in a post hoc analysis of the phase 3 MERIT study in treatment-naïve patients.

METHODS

Patients received maraviroc 300 mg twice daily (n = 360) or efavirenz 600 mg once daily (n = 361), both in combination with zidovudine/lamivudine, for up to 96 weeks. Baseline and on- treatment lipid profiles were analyzed according to National Cholesterol Education Program (NCEP) thresholds.

RESULTS

Baseline characteristics and lipid profiles were comparable between groups. Among patients with total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) below NCEP treatment thresholds at baseline, significantly more efavirenz- than maraviroc-treated patients exceeded those thresholds at 96 weeks (TC: 35% [74/209] vs 11% [20/188], P < .0001; LDL-c: 23% [47/197] vs 8% [15/183], P < .0001). Among patients exceeding NCEP thresholds at baseline, significantly more efavirenz- than maraviroc-treated patients exceeded the thresholds at 96 weeks (TC: 83% [24/29] vs 50% [17/34], P = .0084; LDL-c: 86% [19/22] vs 55% [16/29], P = .0314). Of those with baseline high- density lipoprotein cholesterol (HDL-c) < 40 mg/dL, 43% (56/130) of maravirocand 62% (86/139) of efavirenz-treated patients achieved HDL-c≥40 mg/dL at 96 weeks (P = .0020).

CONCLUSIONS

Maraviroc was not associated with elevations in TC, LDL-c, or triglycerides and showed beneficial effects on lipid profiles of dyslipidemic patients.

A multicenter, randomized, double-blind trial of everolimus versus azathioprine and placebo to maintain steroid-induced remission in patients with moderate-to-severe active Crohn's disease

OBJECTIVES

A prospective study was undertaken to compare the efficacy of everolimus versus azathioprine or placebo in maintaining steroid-induced remission in active Crohn's disease (CD) and assess the safety and pharmacokinetics of everolimus.

METHODS

This was a randomized, double-blind, placebo-controlled, proof-of-concept study in adults with moderate-to-severe active CD. The patients received oral steroids for a rapid induction of remission plus everolimus 6 mg/day, azathioprine 2.5 mg/kg/day, or placebo as maintenance treatment. The main outcome measure was the treatment success, defined as a steroid-free remission by the end of month 3 and maintained until study cutoff without the use of prohibited efficacy treatments.

RESULTS

Following an interim analysis, the study was terminated before enrollment was completed due to the lack of efficacy. The full intent-to-treat population comprised 138 patients. Only 96 patients who entered the study > or =7 months prior to data cutoff were included in the primary efficacy population. The treatment success was achieved in 13 of 38 everolimus patients, 22 of 36 azathioprine patients, and 8 of 22 placebo patients. Using the Kaplan-Meier estimates at month 7, the incidence of treatment success was 22.0% with everolimus group (95% confidence interval [CI] 6.7-37.3%, P= 0.610 vs placebo), 38.3% with azathioprine group (95% CI 20.6-55.9%, P= 0.500 vs placebo), and 28.8% with placebo group (95% CI 7.7-49.9%). The type and incidence of adverse events in the everolimus cohort were similar to those reported in the approved transplantation indications.

CONCLUSIONS

The safety and tolerability of everolimus (6 mg/day) in patients with active CD were comparable to azathioprine. At this dose, everolimus is not more efficacious in achieving a steroid-free remission in active CD than the comparators.

Determinants of fast marathon performance: low basal sympathetic drive, enhanced postcompetition vasodilatation and preserved cardiac performance after competition

OBJECTIVE

To test the hypothesis that enhanced postexercise vasodilatation is related to sympathetic drive to resistance vessels and to fast marathon performance.

DESIGN

Prospective field study before and after running a marathon.

PARTICIPANTS

51 healthy amateur runners who volunteered to participate. The fastest competitor finished fourth, the slowest 1290 th out of 1324 participants.

INTERVENTIONS

None.

MAIN OUTCOME MEASUREMENTS

Competition time, beat-to-beat blood pressure by the vascular unloading technique, oscillometric blood pressure, beat-to-beat stroke volume by impedance cardiography, total peripheral resistance changes calculated from blood pressure and stroke volume changes, sympathetic modulation of vasomotor tone and parasympathetic modulation of sinus node function by spectral analysis of blood pressure and heart rate variability, baroreceptor reflex sensitivity by the sequence method.

RESULTS

Slow performers, in contrast to fast performers, exhibited a higher 0.1 Hz band of diastolic blood pressure variability before the competition (0.1 Hz BPV) (40.0 (SD 2.39) vs 54.9 (2.47), p<0.001), diminished vasodilatation (-11.3 (4.78) vs -29.4 (3.23), p<0.01) and a decrease in stroke index (-14.9 (3.55) vs +0.9 (3.37), p<0.001) in response to the race. Single and multiple regression analyses further corroborated the findings.

CONCLUSIONS

Fast performance in the marathon is associated with low sympathetic modulation of vasomotor tone, maintained stroke index postcompetition and enhanced exercise-induced vasodilatation. We postulate that maintaining a low level of sympathetic modulation to resistance vessels during the course of training may indicate its appropriateness, thus enabling fast performance by optimal postexercise vasodilatation and by prevention of postcompetition cardiac dysfunction. This will have to be tested in future longitudinal studies.

Exocytotic process as a novel model for mineralization by osteoblasts in vitro and in vivo determined by electron microscopic analysis

The process of biomineralization has been examined during osteoblastic differentiation of bone marrow stroma cells (BMSCs) from embryonic chick in culture and in periosteum itself by a number of different techniques including transmission and scanning electron microscopy. In cell culture of BMSCs at days 20-25, crystals were accumulated extracellularly in the collagen matrix, resulting in large plate-like crystallites and noncollagen associated on the culture disk surface. In contrast, up to days 10-18, mainly intracellular mineralization was visible by numerous needle-like crystal structures in the cell cytoplasm and in vacuoles. After 20-30 days, the crystal content of these vacuoles is released, most probably by membrane fusion to the outside of the cells. Energy-dispersive X-ray analysis (EDX), electron spectroscopic imaging, and electron energy loss spectroscopy demonstrated that Ca, O, and P are located in the intra- and extracellular needle-like crystals. From EDX spectra a Ca/P ratio of 1.3 was estimated for the intracellular structures and a Ca/P ratio of 1.5, for the extracellular material (for comparison, the Ca/P ratio in tibiae is 1.6). X-ray diffraction and quantitative infrared spectral analyses also demonstrated an increase of crystalline bone apatite along the mineralization process. In addition to the finding in vitro, the presence of intracellular needle-like crystals in vacuoles could be demonstrated in vivo in osteoblastic cells of the periosteum in tibia of day 11. The results are in favor of a novel model for mineralization by osteoblasts, in which amorphous Ca/P material is directly secreted via an exocytotic process from vacuoles of the osteoblast, deposited extracellularly, propagated into the collagen fibril matrix, and matured to hydroxyapatite.

Practical considerations on the use of extreme sib-pairs for obesity

OBJECTIVES

The extreme sib-pair approach has been shown to be a powerful strategy to identify susceptibility loci linked to quantitative traits. The body mass index is the usually assessed trait in genetic studies on human obesity. Environmental factors clearly play an important role for this trait. We hypothesized that the low weight of most sibs who were seemingly discordant to the obese index proband was influenced by other environmental and/or genetic factors like restrained eating or psychiatric disorders.

METHODS

A screening questionnaire was sent to parents of all consecutively admitted patients three weeks prior to referral of index probands for inpatient treatment of obesity. The first 320 families were further investigated. Twenty-seven seemingly extremely discordant sib-pairs (ED) were identified and examined in detail.

RESULTS

The low weight of most sibs who were seemingly discordant to the obese index proband was influenced by factors like restrained eating or psychiatric disorders. Only 20% of the interviewed ED could be considered as genuine ED.

CONCLUSION

We conclude that extensive medical evaluation is necessary if the aim is to guarantee genuine ED in family studies for human obesity. Non-paternity deserves specific attention in ED studies.

Towards robotic heart surgery: introduction of autonomous procedures into an experimental surgical telemanipulator system

The introduction of telemanipulator systems into cardiac surgery enabled the heart surgeon to perform minimally invasive procedures with high precision and stereoscopic view. For further improvement and especially for inclusion of autonomous action sequences, implementation of force-feedback is necessary. The aim of our study was to provide a robotic scenario giving the surgeon an impression very similar to open procedures (high immersion) and to enable autonomous surgical knot tying with delicate suture material. In this experimental set-up the feasibility of autonomous surgical knot tying is demonstrated for the first time using stereoscopic view and force feedback.

A highly conserved proapoptotic gene, IKIP, located next to the APAF1 gene locus, is regulated by p53

We describe here the identification and initial characterization of a novel human gene termed IKIP (I kappa B kinase interacting protein) that is located on chromosome 12 in close proximity to APAF1 (apoptotic protease-activating factor-1). IKIP and APAF1 share a common 488 bp promoter from which the two genes are transcribed in opposite directions. Three IKIP transcripts are generated by differential splicing and alternative exon usage that do not show significant homology to other genes in the databases. Similar to APAF1, expression of IKIP is enhanced by X-irradiation, and both genes are dependent on p53. Moreover, IKIP promotes apoptosis when transfected into endothelial cells. We conclude that IKIP is a novel p53 target gene with proapoptotic function.

Cardiovascular risk factors in overweight German children and adolescents: relation to gender, age and degree of overweight

OBJECTIVE

So far in Europe, no large studies have been published on the frequencies of the cardiovascular risk factors hypertension and dyslipidaemia in overweight children.

METHODS

Diagnosis of hypertension, decreased HDL-cholesterol, increased triglycerides, total and LDL-cholesterol were documented for 1004 overweight children and adolescents (aged 4-8 years, 52% girls, BMI-SDS in median 2.43) referred to four obesity centres. Hypertension and dyslipidaemia were defined by cut off points above the 95th percentile of healthy children. Multivariate linear regression was conducted for the dependent variables systolic and diastolic blood pressure, triglycerides, HDL-, LDL-, and total cholesterol, including gender, degree of overweight (SDS-BMI) and age as independent variables.

RESULTS

Thirty-seven percent of the children studied suffered from hypertension, 27% displayed increased total cholesterol, 26% increased LDL-cholesterol, 20% increased triglycerides and 18% decreased HDL-cholesterol. Seventy percent of all children had at least one unfavourable cardiovascular risk factor. Hypertension and dyslipidaemia were observed in any age group and in any degree of overweight at least twofold above the suspected rate of 5%. SDS-BMI was significantly related to blood pressure (systolic: coefficient 7.26, p < 0.001, diastolic: coefficient 3.21, p < 0.001), weakly to triglycerides (coefficient 0.12, p = 0.007), slightly negatively to HDL-cholesterol (coefficient -0.06, p = 0.001) and not related to total and LDL-cholesterol. Age was positively related to blood pressure (systolic: coefficient 2.436, p < 0.001, diastolic: coefficient 0.54, p < 0.001) and negatively to HDL cholesterol (coefficient -0.02, p < 0.001).

CONCLUSION

Cardiovascular risk factors were frequently present in a large collective of overweight European children and adolescents. They occurred mostly independently of age, gender and degree of overweight. Therefore, screening for cardiovascular risk factors seems meaningful at any age and degree of overweight in childhood.

Net radiation balance for two forested slopes on opposite sides of a valley

Measurements of the net radiation balance of two forested sites on the opposite slopes of a valley in south-western Germany, made over 3 years, are presented in this study. Radiation sensors were mounted horizontally on two measurement towers above two beech stands. The direct part of the measured short-wave incoming radiation was adjusted according to the slope's angle to convert horizontally measured radiation data into surface-parallel radiation fluxes. During periods when contemporaneous measurements of slope-parallel and horizontal radiation fluxes were available, the calculation of surface-parallel radiation fluxes from the horizontally recorded net radiation components were compared with measured values. The net radiative fluxes parallel to the slopes were calculated for a period of 36 months and analysed. Results show that the different aspects of both sites cause significant differences of the net radiation balance. In June, when the elevation of the sun is highest, incoming solar radiation K downward arrow received on the NE-slope was 9% lower than K downward arrow received on the SW-slope. During the winter months, the differences were much greater and incoming solar radiation to the NE-slope was 50% of that to the SW-slope. Due to the differing solar irradiance, net radiation fluxes were significantly higher on the SW-slope than on the NE-slope. For long-wave radiation only small differences between both slopes could be found. Since radiative fluxes determine the energy balance and hence the microclimate and water balance of a forest stand, these differences in the net radiation balance between the slopes are important for the vegetation.

EKG abnormalities in children and adolescents with symptomatic temporal lobe epilepsy

BACKGROUND

Changes in cardiac rate and rhythm are often found in adult patients with temporal lobe epilepsy (TLE) and could be involved in the pathogenesis of sudden unexplained death (SUDEP). However, little is known about heart rate (HR) variability in pediatric patients with TLE.

OBJECTIVES

To investigate ictal and peri-ictal HR abnormalities in children and adolescents with medically refractory symptomatic TLE and to determine the influence of focus localization and laterality.

METHODS

Patients younger than 18 years, with drug-resistant unilateral symptomatic TLE and presenting with at least one habitual complex partial seizure (CPS) during presurgical noninvasive video-EEG monitoring, were enrolled. Synchronous single-channel EKG recordings were analyzed during the preictal, ictal, and postictal stages.

RESULTS

Twenty patients fulfilled the inclusion criteria. Seventy-two temporal lobe seizures (TLSs) were analyzed. Ictal tachycardia was found in 71 TLSs (98%), whereas ictal bradycardia was not observed. During preictal stages, tachycardia occurred in 20 seizures and mild bradycardia in 3. In 44 seizures (62%), tachycardia was still present >60 seconds after EEG seizure termination. Cluster analysis revealed significant differences in HR evolution depending on location and side of seizure onset: Early and high HR increase was primarily associated with right mesial TLSs.

CONCLUSIONS

Cardiovascular dysregulation is common during temporal lobe CPSs in children. These results confirm a right hemispheric lateralization of sympathetic cardiac control.

Measuring and modelling plant area index in beech stands

For some beech ( Fagus sylvatica L.) stands with different stand densities the plant area index (PAI) was measured by means of a Licor LAI-2000 plant canopy analyser. The stands are located on the slopes of a valley in south-west Germany and had been treated by different types of silvicultural management (heavy shelterwood felling, light shelterwood felling, control plot). The analyser was used (a) to investigate the light conditions on plots of the same thinning regime, (b) to quantify the differences between the different treatments and (c) to obtain absolute values of PAI for interdisciplinary research. PAI was measured at three different phenological stages (leafless, leaf-unfolding and fully leafed season in 2000) and was found to be about 5.2 for the fully developed canopy on the control plots, 3.2 on the light fellings and about 2.0 for the heavy fellings. In the leafless period PAI was between 1.1 (control) and 0.4 (heavy felling). Measurements made in summer 2000 and summer 2002 were compared, and showed an increase of PAI, especially on the thinned plots. Measurements of photosynthetically active radiation (PAR) above and below the canopy in combination with measured PAI were used to apply Beer's Law of radiation extinction to calculate the extinction coefficient k for different sky conditions and for the different growing seasons on the control plots. The extinction coefficient k for the beech stands was found to be between 0.99 and 1.39 in the leafless period, 0.62 to 0.91 during leaf unfolding and between 0.68 and 0.83 in the fully leafed period. Using PAR measurements and the k values obtained, the annual cycle of PAI was modelled inverting Beer's Law.

Type II diabetes mellitus and impaired glucose regulation in Caucasian children and adolescents with obesity living in Germany

BACKGROUND

Recent studies reported an increased prevalence of type II diabetes mellitus in obese children and adolescents, especially in specific ethnic subgroups. The aim of this study was to determine the prevalence of type II diabetes mellitus and impaired glucose regulation in a large group of Caucasian children and adolescents with obesity living in Germany.

PATIENTS AND METHODS

A total of 520 subjects (237 boys, 283 girls) (mean age: 14.0+/-2.0 y (range 8.9-20.4 y)) with a BMI>97th percentile, BMI-SDS: 2.7+/-0.5 (range 1.9-4.6), who were consecutively admitted to an in-patient obesity unit participated in the study. A 2-h oral glucose tolerance test (1.75 mg of glucose per kilogram of body weight) was performed before entering a weight-loss program and capillary blood glucose concentrations were measured. Patients were categorized into normal glucose regulation, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes. In addition, fasting venous blood was taken to determine the circulating insulin, C-peptide and lipids. Insulin resistance was estimated by homeostatic model assessment.

RESULTS

Type II diabetes was present in 1.5% (n=8) of the patients, two patients were admitted with already diagnosed type II diabetes and six patients were identified with yet unknown diabetes. IFG was detected in 3.7% (n=19) and IGT in 2.1% (n=11) of the patients. All together, in 6.7% (n=35) (95% confidence interval: 4.7-9.2%) of the patients, impaired glucose regulation (IFG, IGT) or diabetes was identified. These patients had a higher BMI-SDS, higher levels of fasting insulin and C-peptide and a higher insulin resistance index than the patients with normal glucose regulation. Risk factors for the occurrence of impaired glucose regulation were a BMI-SDS>2.5 as well as a positive parents' history for diabetes.

CONCLUSIONS

This is the first report on the prevalence of type II diabetes in a large cohort of Caucasian children and adolescents with obesity living in Europe. Impaired glucose regulation and type II diabetes were present in a substantial proportion of the patients studied. Screening for diabetes in severely obese children and adolescents (BMI-SDS>2.5) is therefore recommended. Patients identified with impaired glucose regulation need specific treatment programs in order to prevent progression to diabetes.